A circuit is provided which operates in combination with a matrix switch. The circuit senses a switch closure, stores a pair of output signals representative of the closed switch, cancels the effect of a second switch closure or multiple switch closure during the storage period and resets at the end of the storage period. The circuit includes a plurality of transistor latching means connected to the matrix switch, pairs of which are set by switch closures. Clamping diodes are provided to balance the latching means to prevent spontaneous setting. A switch interlock transistor is included to prevent any subsequent switch closures prior to reset from producing an output signal. A transistor arrangement is also included to cancel the output signals when two or more switches are erroneously closed at the same time. At the end of a selected time period, reset transistors are actuated to reset the circuit to its original state.